CWI Joint Design and Weld Joint Types 2

Question 1

The theoretical throat of a fillet weld is defined as the distance from the joint root to the:

Accepted Answer

Hypotenuse of the largest right triangle inscribed in the weld cross section

Answer

The theoretical throat is the perpendicular distance from the root to the hypotenuse of the largest right triangle that can be inscribed within the fillet weld cross section.

Question 2

For an equal-leg fillet weld with legs at 45°, the theoretical throat is approximately what fraction of the leg size?

Accepted Answer

0.707 × leg size

Answer

For a 45° equal-leg fillet weld, the theoretical throat equals leg size × sin(45°) = leg size × 0.707, which is approximately 70.7% of the leg dimension.

Question 3

Per AWS D1.1, what is the minimum fillet weld size required when the thicker base metal being joined exceeds 3/4 inch (19 mm)?

Accepted Answer

5/16 inch (8 mm)

Answer

AWS D1.1 Table 5.8 specifies a minimum fillet weld size of 5/16 inch when the thicker base metal member exceeds 3/4 inch to ensure adequate fusion and heat input.

Question 4

A plug weld is made by:

Accepted Answer

Depositing weld metal in a hole in the overlapping member to fuse it to the underlying member

Answer

A plug weld is made in a circular hole punched or drilled in one member; weld metal fills the hole and fuses to the surface of the underlying member, joining the two overlapping pieces.

Question 5

The root face (land) in a groove weld joint is included primarily to:

Accepted Answer

Prevent burn-through and provide a surface for the root pass to fuse against

Answer

The root face provides a small flat area at the base of the groove that helps control heat and prevents the arc from burning through while still allowing complete root fusion.

CWI Practice Test

CWI Practice Test

CWI Joint Design and Weld Joint Types 2